1. Field of the Invention
The invention relates in general to fiber optic illuminators and, in particular, to fiber optic illuminators which are light tight, very quiet, thermally protected and protected from moisture damage.
2. Description of the Prior Art
Previous fiber optics light generating systems have recognized that thermal protection is necessary for the various components within the light generating system, the light conduit and the surrounding environment. See, for example, Awai U.S. Pat. Nos. 4,825,341 and 4,922,285, and Robbins U.S. Pat. No. 4,704,660. Previous expedients generally did not recognize that the presence of those elements and features which are necessary to provide good thermal protection is generally inconsistent with the objectives of no light leakage, very low noise level and moisture. exclusion. It was not generally appreciated that the utilization of a very open air flow path or labyrinth for cooling purposes is not inconsistent with these objectives provided the air outlet is somewhat more constricted than the air inlet. It is believed that this constriction results in the formation of a region of positive pressure within the illuminator, the formation and benefits of which were generally not previously appreciated. In general the components of previous fiber optics illumination systems included a high intensity light source, a color wheel or filter assembly, a fan assembly and a low output voltage transformer all mounted within a closed case. Optionally, hot or cold mirrors were previously utilized to reflect visible light and absorb or pass infrared and ultraviolet light. It was generally not appreciated that heavy wattage light bulbs, up to as much as 500 watts or more, could be used as the light source without causing thermal damage and without complicated and expensive heat sinks or other heat dissipation expedients in a system with no light leakage, very low noise emission and with moisture protection. The significance of liquid moisture protection was generally not appreciated.
These and other difficulties of the prior art have been overcome according to the present invention.